In my U.S. Pat. No. 4,638,728 there is disclosed a curved Plexiglas visor on which an electrical resistance heating coil is formed to remove and/or prevent condensation of human breath. The coil, while connected to an electric power source, has sufficient current supplied to it to prevent formation of breath condensate on the visor or to remove the condensate. The prior art devices are fabricated by bonding preformed metal films to the interior surface of the curved Plexiglas visors, i.e., to the surface having the greatest curvature, or by painting or pad printing a layer of copper covered by a silver layer on the curved interior surface. While the prior art devices perform satisfactorily to remove and/or prevent the formation of vapor, the methods of applying the coil are relatively expensive.
Therefore, an object of the invention is to provide a new and improved method of applying an electric conducting film to a cellulose diacetate shield that eventually is curved into the shape of a visor.
Yet an additional object of the invention is to provide a method of silk screening a metal film onto a cellulose diacetate sheet that is bent to form.